Issue with dark mode: Low contrast between background and sponsor logos on landing page

[chris234567]

In dark mode the logos in the sponsors section on the landing page (.PNGs & .SVGs) have low contrast against the background, making them hard to read or visually parse.
Some logos (i.e. "The Hg Foundation") contain black writing, which is difficult to separate from dark blue backround.
This issue does not occur in light mode.